Green Lantern: Beware My Power Former Marine John Stewart witnesses Ganthet's spaceship crash nearby. Ganthet dies of his injuries, and the Power Ring he carries — previously owned by Hal Jordan — attaches itself to Stewart's finger. The ring flies Stewart up to the Justice League Watchtower,[a] where he meets Green Arrow, Martian Manhunter, and Vixen. With the Guardians of the Universe unresponsive and Jordan's apparent death, Stewart and Green Arrow use Ganthet's repaired ship to travel to Oa, which they discover in ruins and the Green Lantern Corps slaughtered. They encounter Thanagarian warrior Shayera Hol, who indicates security footage showing a Rannian ship docking at Oa just before the attack. Shayera explains that the Thanagarian-Rannian war had briefly ended, with Jordan overseeing a joint project using Zeta-Beam technology to benefit both planets. The experiment went haywire, transporting Thanagar into Rann's atmosphere, upsetting the ecosystem of both planets, restarting the war, and apparently killing Jordan and thousands of Thanagarians and Rannians. Shayera accuses Rann of sabotaging the experiment and attacking Oa, but Stewart and Green Arrow insist they investigate further...